I agree - usually with a murder-sucide pact, there is some sort of indication of why they did it - impending jail time, scandal of some sort etc. but in this case - so far there is none.

This is highly dubious that four people in different beds would stay there while shooting was going on. Not even investigate.

Plus - the person involved was a DA investigator - I do not know how much money these guys make - but he was living in a 425K house. Not bad for a public servant.

I theorize its a professional hitman - made this scenario look like a murder sucide. Probably using silencers not to alert anyone, and used the person's gun on himself for the last shot - but homeowner was able to dial 911 before he was killed.